Zinc is an essential mineral that influences numerous cellular processes in the body, including immune function, cell division and proliferation, and defense against free radicals. Dietary zinc also appears to play a role in the prevention and growth of certain cancers. Zinc is naturally present in red meat, seafood, poultry, eggs, cheese, nuts and legumes. You should not take zinc supplements without the advice of your doctor.
Anti-tumor Effects in Prostate Cancer
Some clinical research, including an article published in "Archives of Biochemistry and Biophysics" in 2007, suggests that zinc exerts anti-tumor effects on prostate cancer cells. According to Memorial Sloan-Kettering Cancer Center, supplemental zinc intake of greater than 15 mg/day for 10 years has been shown to decrease the risk of advanced prostate cancer. Very high amounts of supplemental zinc may actually potentiate prostate tumor growth, however; studies have associated excessive zinc supplementation -- more than 100 mg/day -- with an increased risk of prostate cancer, according to to Sloan-Kettering.
Zinc and Other Types of Tumors
Zinc deficiency has been associated with increased risk of certain kinds of cancerous tumors in medical literature. In particular, a relationship between zinc deficiency and esophageal cancer is evidenced in both human and animal studies. A population-based study published in "Journal of the National Cancer Institute" in 2005 showed an inverse relationship between tissue zinc concentration and risk of esophageal cancer. In addition to esophageal tumors, zinc deficiency was shown, in a study published in "Carcinogenesis" in 2006, to promote the occurrence and progression of lingual tumors such as oral cancer among mice lacking the tumor suppressor gene p53.
Zinc and Cancer Treatment
Zinc may also provide some benefits in the treatment of certain kind of cancerous tumors. Some studies suggest zinc supplementation may help reduce symptoms of radiation therapy to treat tumors in the head or neck, such as loss of taste and mouth sores, according to the American Cancer Society. Moreover, according to the ACS, research has linked low zinc levels to larger tumors in people being treated for head and neck cancer. The exact relationship between zinc levels and head and neck cancer tumor development and progression is not known, however.
Warning
Zinc supplements can cause serious side effects, and zinc supplementation is not recommended unless it is prescribed by a doctor. While taking zinc in daily doses of 40 g or less is considered "likely safe," according to MedlinePlus, taking higher amounts of zinc is likely unsafe, especially if taken for prolonged periods of time. High doses of zinc can cause copper deficiency, blood iron problems, stomach pain, fever, depressed immune function, fatigue and increased risk of prostate cancer, according to MedlinePlus. Zinc also has several prescription drug interactions including penicillamine, certain antibiotics and certain cancer treatments.
References
- "Archives of Biochemistry and Biophysics"; Zinc as an Anti-Tumor Agent in Prostate Cancer and in Other Cancers; Renty B. Franklin, et al.; July 2007
- Linus Pauling Institute at Oregon State University; Zinc and Prostate Cancer; Emily Ho, et al.; May 2005
- American Cancer Society: Zinc
- National Cancer Institute; Zinc Deficiency Linked to Increased Risk of Less-Common Form of Esophageal Cancer; February 2005
- "Carcinogenesis"; Zinc Deficiency Potentiates Induction and Progression of Lingual and Esophageal Tumors in P53-Deficient Mice; L.Y. Fong, et al.; July 2006
- "Journal of the National Cancer Institute"; Zinc Concentration in Esophageal Biopsy Specimens Measured by X-Ray Fluorescence and Esophageal Cancer Risk; C. Abnet, et al.; February 2005
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